Tenacity
Brittle
Brittle
Solubility
Soluble
Soluble
Durability
-
-
Specific Gravity
1.9933.30-3.50
1
7.18
👆🏻
Fracture
Uneven
Uneven, ConchoidalWalter Schumann, Conchoidal
Cleavage
Perfect on [100], [010], [001]
Perfect on {110}, poor on {101}, {001} rare
Mohs Hardness
2.55
2
10
👆🏻
Chemical Composition
KCl
Zn 4Si 2O 7(OH) 2H 2OMichael OâDonoghue , Gems, Sixth Edition (2006) More from other references